Laser photocoagulation procedures used to treat retinal tears, diabetic retinopathy, and other retinal disorders are well known and widely used. There are essentially three main delivery devices utilized for the delivery of laser energy: the slit lamp, the laser indirect opthalmoscope and the laser endophotocoagulation probe. The present invention deals with the latter.
Traditional ophthalmic surgical laser systems include a laser source connected to a single core, optical fiber endophotocoagulation probe. The probe is inserted into the eye, allowing for the delivery of spots of laser energy to the target tissue, one spot at a time. Each laser pulse is activated by the depression of a footswitch, and the parameters of the delivered laser pulse are typically controlled by a system control panel. The patient must be kept sedated for the duration of the procedure. This single-shot “step and repeat” approach is time consuming and tedious for the physician. The lengthy duration of the anesthesia required by the procedure, and the number of shots delivered, can put the patient at risk.
Simultaneous delivery of multiple spots in endoprobe therapy is known. For example, U.S. Pat. Nos. 5,921,981, and 6,066,128 and 6,096,028 disclose a single laser source connecting to a single core optical fiber, where the laser energy from the single fiber is simultaneously separated into multiple fibers each with equal laser energy. The advantage of this approach over single fiber endophotocoagulation probe delivery is that the speed of the procedure will be increased as N-fibers in the bundle of fibers yield N spots simultaneously. However, there are potential problems with this approach. For example, a much higher power laser source is required in order to deliver the N spots simultaneously. This is significantly more expensive than traditional systems, and there are limits to the amount of power that can be coupled into a specific fiber diameter and numerical aperture. There are also safety issues. If for some reason the components that separate the energy fail or are partially damaged then non-uniform energy will be delivered through the multi-fiber bundle. In the worst case, all the energy could be transmitted down a single fiber, and could result in significant over-treatment at one target tissue location. The system is also inflexible, as the number of spots delivered is fixed and always equal to the number of fibers in the multi-fiber bundle that receive the divided laser energy.
Accordingly, there is a need for a safe, cost effective, flexible and time-efficient approach to retinal photocoagulation with an endophotocoagulation probe that is not provided by known methods or devices.